METALLACYCLOBUTANE AND CYCLOPROPYL SPECIES ON CU(111) AND CU(110)

Low-energy electron bombardment of cyclopropane submonolayers was used to prepare cyclopropyl and metallacyclobutane species on Cu(110) and Cu(111) surfaces. The thermal chemistry of both species was monitored over the 90-450 K range by taking high-resolution electron energy loss (HREELS) and temperature programmed desorption (TPD) measurements. Cy clization of the metallacyclobutane species, to eliminate cyclopropane , was found to occur at 205 K. The metallacyclobutane species was char acterized by CH stretching losses at 2806 and 2839 cm(-1) for Cu(110) and Cu(111), respectively. The cyclopropyl species was found to underg o ring opening to yield a propene desorption product at 290 K. The obs erved surface chemistry of both of these cyclic C-3 species is compare d with data from the organometallic, catalysis, and surface science li terature.